Ch 28: CNS Flashcards
1
Q
what makes up the central nervous system
A
brain and spinal cord
2
Q
what makes up the peripheral nervous system
A
spinal and cranial nerves
3
Q
what are the two main divisions of the PNS
A
sensory (afferent) division
motor (efferent) division
4
Q
what are the two sensory divisions of the PNS
A
somatic (general & special)
visceral
5
Q
what are the two motor divisions of the PNS
A
somatic
autonomic (visceral)
6
Q
what are the two divisions of the visceral motor (autonomic nervous system)
A
parasympathetic
sympathetic
7
Q
what are the principal functional unit of the CNS
A
neurons
8
Q
what are neuroglial cells
A
provide structural support, protection, and maintain their environment
9
Q
what are astrocytes
A
cell of the CNS
anchor neurons and blood vessels
facilitate the blood brain barrier
repair damaged tissue
10
Q
what is an oligodendrocyte
A
cell of CNS
have extensions that wrap around a CNS axon and myelinate it
11
Q
what is a microglial cell
A
cell of CNS
brain phagocyte
12
Q
what is an ependymal cell
A
cell of CNS
line cavities
have cilia to circulate CSF
produce small amounts of CSF
13
Q
what are schwann cells
A
cell of PNS
myelinate axons of PNS
repair damaged axons
14
Q
what are satellite cells
A
cells of PNS
support cell bodies of PNS axons
15
Q
what are the myelinating cells of the CNS
A
oligodendrocytes
16
Q
what is the myelinating cell of the PNS
A
schwann cells
17
Q
what is the purpose of myelination
A
to allow the action potiental to travel down the axon faster
18
Q
what are the 5 main disorders of the nervous system
A
multiple sclerosis (MS)
creutzfeldt-jakob disease (CJD)
alzheimer (AD)
parkinson disease (PD)
amyotrophic lateral sclerosis (ALS)
19
Q
what are some features of multiple sclerosis (MS)
A
demylination of CNS axons at distinct locations
causes scarring (sclerosis or plaque) which decreases neural transmission
patients can get better temporarily then get bad again once a different area is affected
20
Q
what are the three gene mutations that can cause of multiple sclerosis (MS)
A
mutations in HLA-DR, IL2RA, and IL7RA
21
Q
which mutated gene gives you a 3-fold risk of developing multiple sclerosis (MS)
A
HLA-DRB1*1501
22
Q
what is the environmental factor that can cause multiple sclerosis (MS)
A
being away from the equator
likely cause is lack of vitamin D
23
Q
what is the mechanism of multiple sclerosis (MS)
A
helpter T cells, cytotoxic T cells, and plasma B cells cross the blood brain barrier and enter the CNS
they cause an inflammatory response and kill oligodendrocytes which leads to demyelination and axon degeneration
eventually, we get neuron death and brain atrophy
24
Q
how do helper T 1 cells play a role in multiple sclerosis (MS)
A
they release IFN-y which leads to macrophage activation
25
how do helper T 17 cells play a role in multiple sclerosis (MS)
they release IL17 and IL22 which causes recruitment of leukocytes
26
who is most at risk for multiple sclerosis and when are they typically diagnosed
most common in women
usually diagnosed between 20-40 yrs
27
how does multiple sclerosis (MS) affect the optic nerve
damage of optic nerve leads to optic neuritis (inflammation of optic nerve)
28
how does multiple sclerosis (MS) affect the brainstem
damage of brainstem leads to ataxia (loss of cordination) and nystagmus (uncontrolled eye movements)
29
how does multiple sclerosis affect (MS) the spinal cord
damage of spinal cord leads to motor and sensory impariment, spasticity (stiff muscles), and loss of bladder control
30
what are evoked potentials
a type of diagnostic test for multiple sclerosis
electrodes stimulate neurons to test their activity
31
what are oligoclonal bands
a diagnostic test of multiple sclerosis (MS)
spinal tap is performed to get CSF
it's run using electrophoresis
looking for oligoclonal bands (IgG) in CSF which would indicated MS
32
how is an MRI used for multiple sclerosis (MS)
MRIs are used to look for white matter plaques cause by demyelination
33
what are the three diagnostic tests of multiple sclerosis (MS)
evoked potentials
oligoclonal bands in CSF
MRI
34
what are the three main treatments of multiple sclerosis (MS)
corticosteroids
interferon beta
specific medications
35
what are the two corticosteroids used to treat acute multiple sclerosis (MS)
prednisone
cortisone
36
how do corticosteroids help treat multiple slcerosis (MS)
shorten recovery period after acute attack
helps to restore blood brain barrier
blocks some of the macrophage and lymphocyte activity to stop demylination
37
how does interferon beta treat multiple sclerosis (MS)
affects the function of APCs, T cells, and B cells (plasma cells)
38
what is the definition of a neurodegenerative disease
disease caused by an accumulation of protein aggregates which leads to progressive loss of neurons
39
neurogenerative diseases that cause cognitive changes affect which areas of the brain
cerebral cortex and hippocampus
ex. alzheimer disease
40
neurogenerative diseases that cause movement disorders affect which area of the brain
basal ganglia
ex. parkinson disease
41
neurogenerative diseases that cause limb weakness and difficulty swallowing and breathing affect which area of the brain
spinal cord
ex. amyotrophic lateral sclerosis (ALS)
42
what is the most common demyelinating disorder
multiple sclerosis (MS)
43
what are prion diseases
rapidly progressing neurodegenerative diseases that lead to progressive dementia
ex. CJD
44
what are normal prion proteins
PrPC
cytoplasmic proteins found in all cells but mostly neurons and glial cells
45
what is the mechanism of a prion disease
normal prion proteins (PrPC) undergo misfolding and become (PrPSC)
misfolded prion proteins (PrPSC) are protease resistant and accumulate in the neuronal tissue
causes fatal white matter damage
46
what are the three ways to get a prion disease
sporadicly (randomly)
familial (mutation)
transmitted (inoculation or ingestion)
47
what is the most common prion disease
creutzfeldt-jakob disease (CJD)
48
which age range is most affected by creutzfeldt-jakob disease
60-70 years old
49
what are the three ways to get creutzfeldt-jakob disease (CJD)
sporadic (randomly)
familial (mutations)
iatrogenic (procedure)
50
what is the most common way to get creutzfeldt-jakob disease (CJD)
sporadic (90%) - randomly
51
what is the familial cause of creutzfeldt-jakob disease (CJD)
mutation in PRNP that encodes for misfolded prion proteins
52
what are the three iatrogenic causes of creutzfeldt-jakob disease (CJD)
transplant - corneal/dural
implantation of brain electrodes
contaminated cadaveris hGH (human growth hormone)
53
what are four symptoms of creutzfeldt-jakob disease (CJD)
behavior changes
dementia
involuntary muscle jerking
brain shrinkage
54
typically, how long does someone with creutzfeldt-jakob disease (CJD) live
7 months
55
what is the most common form of dementia in adults older than 60
alzheimer disease
56
what are the two major types of alzheimer disease
familial (early-onset) - mutation
sporadic - random
57
what is the most common type of alzheimer disease
sporadic (90%) - random
58
what are the two prominant features of Alzheimer disease
extracellular amyloid-beta (AB) plaques
intracellular neurofibrillary (tau) tangles
59
explain the mechanism of alzheimer disease
amyloid precursor protein is cut at beta-secretase site instead of normal alpha-secretase site
after gamma-secretase cleaves its spot (the same in both pathways), we're left with an alphabeta monomer which is highly prone to aggregation
aggregation of these monomers leads to amyloid fibrils which causes plaques and tangles, ultimately leading to neuronal damage
60
explain briefly how Tau tangles are formed in Alheimer disease
creation of alphabeta monomor activates kinases that lead to Tau phosphorylation
Tau phosphorylation leads to Tau aggregates
Tau aggregates lead to plaques and tangles that and cause neuronal damage
61
what are the three familial causes of alzheimer disease
amyloid precursor protein (APP gene)
presenilin 1 (PSEN1 gene)
presenilin 2 (PSEN2 gene)
62
what chromosome is the amyloid precursor protein (APP gene) on
chromosome 21
63
how is down syndrome releated to alzheimer disease
those with down syndrome have three copies of chromsome 21
if all three of those copies possess a amyloid precursor protein (APP) gene mutation, it increases their risk for developing Alzheimer disease
64
what two factors are important for the sporadic form of Alzheimer disease
interactions among genetic and environmental factors
65
which three environmental factors can cause alzheimer disease
aluminum in drinking water
large levels of electromaganetic fields
exposure to solvents/pesticides
66
which genetic factor can lead to the sporadic form of alzheimer disease
mutation in apolipoprotein E (apoEA) on chromosome 19
67
what are six symptoms of alzheimer disease
memory disturbances
language deficits
loss of math skills
loss of learned motor skills
mute
inability to walk
68
what are the four ways to test for alzheimer disease
exclusion
MRI
mini mental state exam (MMSE)
post-mortem exam
69
which two things would be seen on a MRI in an alzheimer patient
brain atrophy
enlarged ventricles
70
what two things are seen on a post-mortem exam in a patient with alzheimer
widened sulci and thin gyri of temporal and frontal lobes
definitive diagnostic tool
71
what are three things used to treat alzheimer disease
cholinesterase inhibitors
antipsychotics/mood stabilizers
cognitive stimulation therapy
72
when are cholinesterase inhibitors most effective in treating alzheimer disease
mild disease states: 6-12 months
73
what is the average lifespan of someone with alzheimers after diagnosis
8 years
74
what is the main function of the basal ganglia
controls movement to ensure it is smooth
75
what are the three pathways the basal ganglia influence
direct pathway
indirect pathway
nigrostriatal pathway
76
what is the direct pathway
increases motor function - movement
increased further by dopamine
77
what are the four areas involved in the direct pathway
cortex
striatum
globus pallidus internus
thalamus
78
what is the indirect pathway
decreases motor function - no movement
inhibited further by dopamine
79
what are the six areas involved in the indirect pathway
cortex
striatum
globus pallidus externus
globus pallidus internus
thalamus
substantia nigra
80
what is the nigrostriatal pathway
purely excitatory pathway
influences both pathways to help control movement
81
what is parkinson disease
degenerative disorder of basal ganglia
82
what is the mechanism of parkinson disease
accumulation of protein aggregates cause destruction of dopaminergic neurons from substantia nigra
less SN neurons means less dopamine
less dopamine means less inhibiting of D2 pathway and less stimulating D1 pathway
causes overall reduction in movement
83
what are the two causes of primary parkinsonism
mostly idiopathic - unknown
familial - inherited
84
what are the four causes of secondary parkinsonism
drug induced
encephalitis
trauma
other neurodegenerative disorders
85
what is the environmental toxin that can cause parkinson disease
MPTP
used for animal studies but can be accidentally taken by humans too
86
15% of those with parkinson disease have what
a first-degree relative who also has the disease
87
what are the two gene mutations that can lead to parkinson disease
LRRK2 (PARK8)
SNCA
88
how does mutation in LRRK2 (PARK8) gene cause parkinson disease
dominant mutation that encodes for dardarin protein
causes gain of function
89
how does mutation in SNCA gene cause parkinson disease
encodes for alpha-synuclein
expressed mostly in the substantia nigra
forms aggregates which are toxic to neurons
90
what is a major component of Lewy bodies
alpha-synuclein
91
what are the six major symptoms of parkinson disease
resting tremor
mask-like face (no emotions)
rigidity
postural instability
bradykinesia (slow movement)
flexed joints
92
what is amyotrophic lateral sclerosis (ALS)
aka lou gehrig disease
degeneration of upper and/or lower motor neurons
93
which age range is at most risk of developing amyotrophic lateral sclerosis (ALS)
mostly men between 40-70 years
94
what are six possible causes of sporadic amyotrophic lateral sclerosis (ALS)
excessive glutamate
immune disturbances
apoptotic factors
viruses
heavy metals
enzyme abnormalities
95
what two factors are needed to cause sporadic amyotrophic lateral sclerosis (ALS)
genetic and environmental factors
96
what are three mutations that can lead to familial amyotrophic lateral sclerosis (ALS)
hexanucleotide repeat expansion in C9orf72
superoxide dismutase 1 (SOD-1)
SPTLC1
97
how does a mutation in C9orf72 lead to familial amyotrophic lateral sclerosis (ALS)
dominant, expanded repeats that causes neuronal deposits (TDP-43 inclusions)
98
which gene is most responsible for familial amyotrophic lateral sclerosis (ALS)
C9orf72 (40%)
99
how does a mutation in superoxide dismutase 1 lead to familial amyotrophic lateral sclerosis (ALS)
dominant mutation that causes a misfolded protein to aggregate
aggregation leads to apoptosis of neurons
100
how do mutations in SPTLC1 lead to familial amyotrophic lateral sclerosis (ALS)
dominant mutation of protein coding gene
affects mostly children 4 and up - juvenile ALS
101
mutation of which gene leads to juvenile, familal amyotrophic lateral sclerosis (ALS)
mutation in SPTLC1
102
what is guamanian amyotrophic lateral sclerosis (ALS)
type of amyotrophic lateral sclerosis caused by neurotoxin in seed of diet
103
what is the neurotoxin that is believed to cause guamanian amyotrophic lateral sclerosis (ALS)
BMAA
104
what are the two unique symptoms of guamanian amyotrophic lateral sclerosis (ALS)
dementia
parkinson like symptoms
105
what is the main symptom of amyotrophic lateral sclerosis (ALS)
loss of lower and upper motor neurons
106
what are the four symptoms of loss of lower motor neurons in amyotrophic lateral sclerosis (ALS) patients
denervation of muscles
muscle atrophy
weakness
fasciculations (muscle twitches)
107
what are the three symptoms of loss of upper motor neurons in amyotrophic lateral sclerosis (ALS) patients
paresis (weakness)
hyperreflexia
spasticity (stiff muscles)
108
what is the life expectancy of someone with amyotrophic lateral sclerosis (ALS)
3 to 5 years after diagnosis
109
what ultimately kills someone with amyotrophic lateral sclerosis (ALS)
paralysis of diaphragm and respiratory infection
110
what are the two drugs used to slow progression of amyotrophic lateral sclerosis (ALS)
rilutek (riluzole)
antioxidant vitamins
111
what are three antioxidant vitamins used to slow progression of amyotrophic lateral sclerosis (ALS)
vitamin E
vitamin C
beta-carotene
112
what are the three things used to treat symptoms of amyotrophic lateral sclerosis (ALS)
NSAIDS for pain
baclofen (stiffness)
tizanidine (stiffness)
